The AK86-L from AOpen is a solid board. After the initial issues with memory it was very stable, more so than the K8NNXP which has an intermittent tendency to reboot at odd times. The price is great also - at 96$ from newegg one will be hard pressed to find a cheaper Athlon 64 board than the AK86-L. Some of the things on the accessories side are a bit lacking; the board does no include extra PCI USB brackets for the additional headers found on the mainboard nor does it come with Firewire. Both of these are pretty minor issues considering the price which undercuts the K8NNXP by a whopping 80$. Staples like AOpen's SilentTek (covered here extensively) are additional features that make the AK86-L even more attractive to the end user.
The AK86 does not skimp on the performance front. For most tests it was faster than the Nforce 3 based Gigabyte and in Call of Duty it trounced the K8NNXP thoroughly but in most of our testing situations it did not seem that the faster HyperTransport bus speed made a huge difference. This is especially true in the synthetic and office type benchmarks where the benchmark results were fairly similar between the two boards.
AOpen's AK86-L and VIA's K8T800 makes a strong first impression in our lab. VIA has really redeemed themselves over the performance inhibited KT400/600 line on the older Athlon XP and has put together a compelling solution for those that are in the Athlon 64 market. For the most part, the performance between the Nforce 3 and the K8T800 were fairly close. The AK86-L comes as a highly recommended solution. Pair one of these up with an Athlon 64 3000+ and the end user will have a screamer of a system for roughly 300$.